Sustainability:
from the verb to sustain meaning: to hold up; to bear; to support; to provide for;
to maintain; to sanction; to keep going; to keep up; to prolong; to support the
life of. (Chambers Concise Dictionary)

Petronas Twin Towers, Kuala Lumper

O'Riorden (1985) commented on the difficulty of defining
sustainability, describing its definition as an:

'Exploration into a tangled conceptual jungle where
watchful eyes lurk at every bend'

Spedding (1996) commented that perhaps this was the reason for:

'The remarkable number of books, chapters and papers, that
even use 'sustainable' or 'sustainability' in the title but do not define either
term'

Wilson (1992) stated:

'The raging monster upon the land is population growth, in
its presence, sustainability is but a fragile theoretical construct'

Definitions of sustainability

The definitions given below encompass all aspects of this
subject. The areas of sustainable agriculture and sustainable development are
dealt with in more detail later in the subject:

1. Brundtland(1987): This is the most
commonly quoted definition and it aims to be more comprehensive than most:

Sustainable development is development that meets the needs
of the present without compromising the needs of future generations to
meet their own needs.

It contains within it two key concepts:

The concepts of needs, in particular the essential needs of
the worlds poor, to which overriding priority should be given, and:

The idea of limitations imposed by the state of technology
and social organization on the environments ability to meet present and future
needs.

2. Harwood (1990):

Sustainable agriculture is a system that can evolve indefinitely
toward greater human utility, greater efficiency of resource use
and a balance with the environment which is which is favourable to humans and
most other species.

3. Pearce, Makandia & Barbier (1989)

Sustainable development involves devising a social and
economic system, which ensures that these goals are sustained, i.e. that real incomes
rise, that educational standards increase, that the health of the nation
improves, that the general quality of life is advanced.

4. Conway & Barbier (1990) from 1,2 &
3:

We thus define agricultural sustainability as the
ability to maintain productivity, whether as a field or farm or nation. Where
productivity is the output of valued product per unit of resource input.

5. Daly (1991) then argued that:

Lack of a precise definition of the term 'sustainable
development' is not all bad. It has allowed a considerable consensus to evolve
in support of the idea that it is both morally and economically wrong to treat
the world as a business in liquidation.

Pause for thought....... The world, a
business in liquidation, would you consider this a sensible way for
international powers to approach the concept of sustainability (at any level),
what are the reasons for your answer?

6. Heinen (1994)

No single approach to 'sustainable development' or framework
is consistently useful, given the variety of scales inherent in different
conservation programmes and different types of societies and institutional
structures

7. IUCN, UNEP, WWF (1991):

Sustainable development, sustainable growth, and sustainable
use have been used interchangeably, as if their meanings were the same. They are
not. Sustainable growth is a contradiction in terms: nothing physical can grow indefinitely.
Sustainable use, is only applicable to renewable resources. Sustainable
development is used in this strategy to mean: improving the quality of human
life whilst living within the carrying capacity of the ecosystems.

8. Holdgate (1993):

Development is about realising resource potential,
Sustainable development of renewable natural resources implies respecting limits
to the development process, even though these limits are adjustable by
technology. The sustainability of technology may be judged by whether it
increases production, but retains it other environmental and other limits.

9. Pearce (1993):

Sustainable development is concerned with the development of
a society where the costs of development are not transferred to future
generations, or at least an attempt is made to compensate for such costs.

Pause for thought.......List 3 historical events or actions where the costs have been transferred to
future generations

10. HMSO (1994):

Most societies want to achieve economic development to secure
higher standards of living, now and for future generations. They also seek to
protect and enhance their environment, now and for their children. Sustainable
development tries to reconcile these two objectives.

Analysis of sustainability

Riley (1992) pointed out that the level of analysis of
sustainability is important and quoted the following table:

Quality of the natural environment; human welfare &
equity mechanisms; international agricultural research & development

Control of pollution; terms of trade; distribution

Pause for thought......Before moving on
to the next section, see if you can categorize different levels or types of
sustainability

Types of Sustainability

There are two commonsense
propositions that would probably command general support, before categorizing
the different types of sustainability:

A sustainable system or
process must be based on resources that will not be exhausted over a
reasonable period (sometimes expressed as the 'long term')

A sustainable system or
process must not generate unacceptable pollution externally or internally

Biological sustainability

No individual life form can be sustainable indefinitely, since
all must die at some point in time. Therefore:

Preservation of individual life is only possible for limited
periods (limited sustainability)

Individual species, ecosystems and habitats can be sustained
as they involve reproductive and other essential processes - without which
they would cease to exist

However, many of these entities change and evolve as a
result of such processes therefore:

Sustainable processes does not necessarily lead to
sustainable entities (i.e. precisely as they were originally)

Most biological systems have physical components, therefore
there is considerable overlap between the use of biological and physical
resources

Pause for thought........List 5 points in an agricultural system where the actions of the farmer directly
effects biological sustainability.

Sustainable resource use

Newly manufactured
fence posts, but are they from a sustainable wood supply?

Resources such as water and energy can be used up, but never
destroyed. They may be changed in form, be recyclable or difficult to recapture.
There is a difference between using a resource and using it up. For example, the
countryside. Viewing the hills in the Lake District is not using up the
resource, walking in the hills may (eventually) destroy them. The diagram below
illustrate the flow of resources through a 'typical' rural community.

Source: Pretty, J. N. The Living Land (1998)

Pause for thought............The arrows
in the flow chart above, outline the flows of money through the rural
sector, can you suggest any free resources the farmer receives, and of what use
are they?

Non living resources

Some resources are limited, other resources if not used now,
will not remain. The most obvious example being sunlight. If the solar
radiation received today is not trapped and utilized, it will not be available
tomorrow . Nor will the rate that it is used today effect the amount that can be
used tomorrow. The sun however is not an infinite resource and is slowly (albeit
very slowly) running down. Non-living resources may largely remain intact, though they
may change greatly in form (consider soil erosion, radiation loss and weathering
of rock). Resources such as fossil fuels are totally changed when used and
cannot be recreated on any reasonable time scale. But they serve no purpose if
left unused. The use of fossil fuels is entirely necessary to discover and
exploit other resources for energy production. They make possible the
construction of dams for hydropower and windmills for wind power. In other
words, we are using the limited resource to find the means not to use, or at
least limit its rate of use in the future.

Pause for thought.......If a resource
is limited, is there any benefit of leaving it totally unused?

Gas and petrol are
both derived from unsustainable resources

Living resources

Living resources do not remain static. A dairy cow which is not
milked may not provide any milk in the future and may eventually die
and be unavailable for any purpose.

The use of living resources may have to be considered over a
relatively short period or be related to populations (plant and animal) capable
of reproduction. This has given rise to the concept of sustainable
harvesting, taking only such proportion of the population as can be
continued over time, depending on reproductive rates in animals and seed numbers
in plants

Consider the fact.........All living things must eventually die:
thus, a tree not used as a resource will eventually die and decay -
liberating the same amount of CO2 as if it had been burnt.

Economic and social sustainability

Economics is about the efficient use of resources, usually
expressed in monetary terms. In this sense, the theories regarding sustainable
use of resources can be applied to economic sustainability, except that, in
monetary terms, one resource can generally substitute for another. The concept
of economic sustainability is subject, on all levels, to different inputs and
outputs. The economic sustainability of a farm is subject to the viability
of, and markets for, an enterprise or product. The economic sustainability of a
nation is subject to the whole economy on local, national and international
level.

It is often argued that something is not sustainable if it
depends on unacceptable practices, for instance, in the 18th
Century it was acceptable to send small boys up chimneys, cheap but morally
wrong and socially unacceptable.

The subject of economic and social sustainability is
alluded to in great detail in the outside links in the sustainable development
section.